One of the best buffer choice for pH = 8.0 is Tris with Ka value of 6.3 x 10^-9.
To support this answer, we first calculate for the pKa value as the negative logarithm of the Ka value:
pKa = -log Ka
For Tris, which is an abbreviation for 2-Amino-2-hydroxymethyl-propane-1,3 -diol and has a Ka value of 6.3 x 10^-9, the pKa is
pKa = -log Ka
= -log (6.3x10^-9)
= 8.2
We know that buffers work best when pH is equal to pKa:
pKa = 8.2 = pH
Therefore Tris would be a best buffer at pH = 8.0.
0.3268 moles of PC15 can be produced from 58.0 g of Cl₂ (and excess
P4)
<h3>How to calculate moles?</h3>
The balanced chemical equation is

The mass of clorine is m(
) = 58.0 g
The amount of clorine is n(
) = m(
)/M(
) = 58/70.906 = 0.817 mol
The stoichiometric reaction,shows that
10 moles of
yield 4 moles of
;
0.817 of
yield x moles of 
n(
) = 4*0.817/10 = 0.3268 mol
To know more about stoichiometric reaction, refer:
brainly.com/question/14935523
#SPJ9
Chicken noodle soup would be considered a mixture.
Answer:
0.1 mole of CH₄
Explanation:
From the question given above, the following data were obtained:
Volume of CH₄ = 2.24 L
Number of mole of CH₄ =?
The number of mole of CH₄ can be obtained as follow:
Recall:
1 mole of a gas occupy 22.4 L at stp. This implies that 1 mole of CH₄ occupies 22.4 L at stp.
22.4 L = 1 mole of CH₄
Therefore,
2.24 L = 2.24 × 1 mole of CH₄ / 22.4
2.24 L = 0.1 mole of CH₄.